Chris Carpenter left Cardinals camp earlier this week with what was described as a neck injury, but after several days of testing by specialists he’s been diagnosed with nerve irritation in his shoulder.

Derrick Goold of the St. Louis Post Dispatchreports that Carpenter is “out indefinitely” with an injury similar to one he had in 2008 and “is going to have to recover then re-strengthen his shoulder” before rejoining the rotation.

In other words, it’s going to be a while.

Carpenter had already been scratched from his Opening Day assignment, with Kyle Lohse taking his place, and Lance Lynn will step into his rotation spot for however long is needed.

As part of a two-year contract signed in September the 36-year-old Carpenter is owed $21 million and for the second straight year the Cardinals must now replace their No. 1 starter before the season begins, although at least Adam Wainwright looks healthy again after missing all of 2011.